As the Trump-Russia scandal and investigation have gradually marched closer to Donald Trump’s front door, he and his legal team and political allies have been floating various possible defenses. Some of them have been harebrained legal schemes, while others have been designed to influence the court of public opinion. It’s still not clear that Trump’s attorneys have any coherent plan for protecting him. We do, however, know that Trump just lost what would have been one of his key defenses.

Donald Trump is eventually going to be proven guilty on everything from treason-related charges to money laundering. He’s led a lifetime of crime. His crimes during the election weren’t the beginning of his crime spree; they only served to amplify his lifelong pattern. Yet the swiftest way to prove Trump guilty on something, and thus get him out of office, is the same path that prosecutors took for forcing Richard Nixon out: obstruction of justice. Thursday night’s obstruction bombshell just changed everything.

It’s long been known that Special Counsel Robert Mueller is pursuing Donald Trump for obstruction of justice in relation to the firing of FBI Director James Comey and the attempted coverup of Donald Trump Jr’s Russia meeting. But now we may have a quicker way of proving obstruction. The New York Times just confirmed that Trump asked several key Republican Senators to end the Russia investigation (link). This is an easy case to prove, and the Senators themselves will easily decide to cooperate against Trump in an effort to avoid facing criminal charges themselves. It gets even uglier for Trump.

Former prosecutor Joyce Vance appeared on Rachel Maddow’s MSNBC show on Thursday evening and explained that when it comes to this kind of obstruction of justice, ignorance of the law is not considered a valid legal defense. In other words, Donald Trump can’t simply claim that he was too naive about politics to realize he was committing a felony by asking the GOP to scuttle the investigation. Trump just lost what would have been a key defense.